3 # Script helping make fast-forwarding histories while still rebasing
4 # upstream deltas when working on Debian packaging
6 # Copyright (C)2017,2018 Ian Jackson
8 # This program is free software: you can redistribute it and/or modify
9 # it under the terms of the GNU General Public License as published by
10 # the Free Software Foundation, either version 3 of the License, or
11 # (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program. If not, see <http://www.gnu.org/licenses/>.
24 # git-debrebase [<options>] new-upstream-v0 \
25 # <new-version> <orig-commitish> \
26 # [<extra-orig-name> <extra-orig-commitish> ...] \
27 # [<git-rebase options>...]
29 # git-debrebase [<options> --] [<git-rebase options...>]
30 # git-debrebase [<options>] analyse
31 # git-debrebase [<options>] breakwater # prints breakwater tip only
32 # git-debrebase [<options>] launder # prints breakwater tip etc.
33 # git-debrebase [<options>] stitch [--prose=<for commit message>]
34 # git-debrebase [<options>] downstream-rebase-launder-v0 # experimental
36 # git-debrebase [<options>] convert-from-gbp [<upstream-git-rev>]
37 # git-debrebase [<options>] convert-to-gbp
39 # problems / outstanding questions:
41 # * dgit push with a `3.0 (quilt)' package means doing quilt
42 # fixup. Usually this involves recommitting the whole patch
43 # series, one at a time, with dpkg-source --commit. This is
44 # terribly terribly slow. (Maybe this should be fixed in dgit.)
46 # * dgit push usually needs to (re)make a pseudomerge. The "first"
47 # git-debrebase stripped out the previous pseudomerge and could
48 # have remembeed the HEAD. But it's not quite clear what history
49 # ought to be preserved and what should be discarded. For now
50 # the user will have to tell dgit --overwrite.
52 # To fix this, do we need a new push hook for dgit ?
54 # * Workflow is currently clumsy. Lots of spurious runes to type.
55 # There's not even a guide.
57 # * There are no tests.
59 # * new-upstream-v0 has a terrible UI. You end up with giant
60 # runic command lines.
62 # One consequence of the lack of richness it can need --force in
63 # fairly sensible situations and there is no way to tell it what
64 # you are really trying to do, other than just --force. There
65 # should be an interface with some default branch names.
67 # * There should be a standard convention for the version number,
68 # and unfinalised or not changelog, after new-upstream.
70 # * Handing of multi-orig dgit new-upstream .dsc imports is known to
71 # be broken. They may be not recognised, improperly converted, or
72 # their conversion may be unrecognised.
74 # * Docs need writing and updating. Even README.git-debrebase
75 # describes a design but may not reflect the implementation.
77 # * We need to develop a plausible model that works for derivatives,
78 # who probably want to maintain their stack on top of Debian's.
79 # downstream-rebase-launder-v0 may be a starting point?
83 use Debian::Dgit qw(:DEFAULT :playground);
90 use Getopt::Long qw(:config posix_default gnu_compat bundling);
92 use File::FnMatch qw(:fnmatch);
94 our ($opt_force, $opt_noop_ok);
96 our $us = qw(git-debrebase);
100 die "bad usage: $m\n";
104 my ($k, $optional) = @_;
106 my @cmd = qw(git config -z);
107 push @cmd, qw(--get-all) if wantarray;
109 my $out = cmdoutput_errok @cmd;
111 fail "missing required git config $k" unless $optional;
114 my @l = split /\0/, $out;
115 return wantarray ? @l : $l[0];
122 my $dd = new Data::Dumper [ $v ];
123 Terse $dd 1; Indent $dd 0; Useqq $dd 1;
129 my $data = (git_cat_file $objid, 'commit');
130 $data =~ m/(?<=\n)\n/ or die "$objid ($data) ?";
134 sub D_UPS () { 0x02; } # upstream files
135 sub D_PAT_ADD () { 0x04; } # debian/patches/ extra patches at end
136 sub D_PAT_OTH () { 0x08; } # debian/patches other changes
137 sub D_DEB_CLOG () { 0x10; } # debian/ (not patches/ or changelog)
138 sub D_DEB_OTH () { 0x20; } # debian/changelog
139 sub DS_DEB () { D_DEB_CLOG | D_DEB_OTH; } # debian/ (not patches/)
141 our $playprefix = 'debrebase';
147 sub in_workarea ($) {
150 my $r = eval { $sub->(); };
151 { local $@; changedir $maindir; }
155 sub fresh_workarea () {
156 $workarea = fresh_playground "$playprefix/work";
157 in_workarea sub { playtree_setup };
160 sub get_differs ($$) {
162 # This resembles quiltify_trees_differ, in dgit, a bit.
163 # But we don't care about modes, or dpkg-source-unrepresentable
164 # changes, and we don't need the plethora of different modes.
165 # Conversely we need to distinguish different kinds of changes to
166 # debian/ and debian/patches/.
171 my ($opts, $limits, $fn) = @_;
172 my @cmd = (@git, qw(diff-tree -z --no-renames));
174 push @cmd, "$_:" foreach $x, $y;
175 push @cmd, '--', @$limits;
176 my $diffs = cmdoutput @cmd;
177 foreach (split /\0/, $diffs) { $fn->(); }
180 $rundiff->([qw(--name-only)], [], sub {
181 $differs |= $_ eq 'debian' ? DS_DEB : D_UPS;
184 if ($differs & DS_DEB) {
186 $rundiff->([qw(--name-only -r)], [qw(debian)], sub {
188 m{^debian/patches/} ? D_PAT_OTH :
189 $_ eq 'debian/changelog' ? D_DEB_CLOG :
192 die "mysterious debian changes $x..$y"
193 unless $differs & (D_PAT_OTH|DS_DEB);
196 if ($differs & D_PAT_OTH) {
198 $differs &= ~D_PAT_OTH;
200 $differs |= D_PAT_OTH;
201 no warnings qw(exiting); last;
203 $rundiff->([qw(--name-status -r)], [qw(debian/patches/)], sub {
204 no warnings qw(exiting);
205 if (!defined $mode) {
208 die unless s{^debian/patches/}{};
210 if ($mode eq 'A' && !m/\.series$/s) {
212 } elsif ($mode eq 'M' && $_ eq 'series') {
213 my $x_s = (git_cat_file "$x:debian/patches/series", 'blob');
214 my $y_s = (git_cat_file "$y:debian/patches/series", 'blob');
215 chomp $x_s; $x_s .= "\n";
216 $ok = $x_s eq substr($y_s, 0, length $x_s);
221 $differs |= $ok ? D_PAT_ADD : D_PAT_OTH;
223 die "mysterious debian/patches changes $x..$y"
224 unless $differs & (D_PAT_ADD|D_PAT_OTH);
227 printdebug sprintf "get_differs %s, %s = %#x\n", $x, $y, $differs;
232 sub commit_pr_info ($) {
234 return Data::Dumper->dump([$r], [qw(commit)]);
237 sub calculate_committer_authline () {
238 my $c = cmdoutput @git, qw(commit-tree --no-gpg-sign -m),
239 'DUMMY COMMIT (git-debrebase)', "HEAD:";
240 my ($h,$m) = get_commit $c;
241 $h =~ m/^committer .*$/m or confess "($h) ?";
245 sub rm_subdir_cached ($) {
247 runcmd @git, qw(rm --quiet -rf --cached --ignore-unmatch), $subdir;
250 sub read_tree_subdir ($$) {
251 my ($subdir, $new_tree_object) = @_;
252 rm_subdir_cached $subdir;
253 runcmd @git, qw(read-tree), "--prefix=$subdir/", $new_tree_object;
256 sub make_commit ($$) {
257 my ($parents, $message_paras) = @_;
258 my $tree = cmdoutput @git, qw(write-tree);
259 my @cmd = (@git, qw(commit-tree), $tree);
260 push @cmd, qw(-p), $_ foreach @$parents;
261 push @cmd, qw(-m), $_ foreach @$message_paras;
262 return cmdoutput @cmd;
265 our @fproblem_force_opts;
266 our $fproblems_forced;
267 our $fproblems_tripped;
270 if (grep { $_ eq $tag } @fproblem_force_opts) {
272 print STDERR "git-debrebase: safety catch overridden (-f$tag): $msg\n";
274 $fproblems_tripped++;
275 print STDERR "git-debrebase: safety catch tripped (-f$tag): $msg\n";
279 sub fproblems_maybe_bail () {
280 if ($fproblems_forced) {
282 "%s: safety catch trips: %d overriden by individual -f options\n",
283 $us, $fproblems_forced;
285 if ($fproblems_tripped) {
288 "%s: safety catch trips: %d overriden by global --force\n",
289 $us, $fproblems_tripped;
292 "%s: safety catch trips: %d blockers (you could -f<tag>, or --force)",
293 $us, $fproblems_tripped;
297 sub any_fproblems () {
298 return $fproblems_forced || $fproblems_tripped;
301 # classify returns an info hash like this
303 # Hdr => # commit headers, including 1 final newline
304 # Msg => # commit message (so one newline is dropped)
306 # Type => (see below)
308 # Ix => $index # ie 0, 1, 2, ...
310 # Differs => return value from get_differs
312 # IsDggitImport => 'orig' 'tarball' 'unpatched' 'package' (as from dgit)
314 # NewMsg => # commit message, but with any [dgit import ...] edited
315 # # to say "[was: ...]"
325 # has additional entres in classification result
326 # Overwritten = [ subset of Parents ]
327 # Contributor = $the_remaining_Parent
329 # DgitImportUnpatched
330 # has additional entry in classification result
331 # OrigParents = [ subset of Parents ]
333 # BreakwaterUpstreamMerge
334 # has additional entry in classification result
335 # OrigParents = [ subset of Parents ] # singleton list
338 # has additional entry in classification result
341 sub parsecommit ($;$) {
342 my ($objid, $p_ref) = @_;
343 # => hash with CommitId Hdr Msg Tree Parents
344 # Parents entries have only Ix CommitId
345 # $p_ref, if provided, must be [] and is used as a base for Parents
350 my ($h,$m) = get_commit $objid;
352 my ($t) = $h =~ m/^tree (\w+)$/m or die $objid;
353 my (@ph) = $h =~ m/^parent (\w+)$/mg;
363 foreach my $ph (@ph) {
365 Ix => scalar @$p_ref,
377 my $r = parsecommit($objid, \@p);
381 $p->{Differs} = (get_differs $p->{CommitId}, $t),
384 printdebug "classify $objid \$t=$t \@p",
385 (map { sprintf " %s/%#x", $_->{CommitId}, $_->{Differs} } @p),
389 my ($type, @rest) = @_;
390 $r = { %$r, Type => $type, @rest };
392 printdebug " = $type ".(dd $r)."\n";
398 $r = { %$r, Type => qw(Unknown), Why => $why };
399 printdebug " ** Unknown\n";
403 my $claims_to_be_breakwater =
404 $r->{Msg} =~ m{^\[git-debrebase breakwater.*\]$}m;
407 if ($claims_to_be_breakwater) {
408 return $unknown->("single-parent git-debrebase breakwater \`merge'");
410 my $d = $r->{Parents}[0]{Differs};
411 if ($d == D_PAT_ADD) {
412 return $classify->(qw(AddPatches));
413 } elsif ($d & (D_PAT_ADD|D_PAT_OTH)) {
414 return $unknown->("edits debian/patches");
415 } elsif ($d & DS_DEB and !($d & ~DS_DEB)) {
416 my ($ty,$dummy) = git_cat_file "$p[0]{CommitId}:debian";
418 if ($d == D_DEB_CLOG) {
419 return $classify->(qw(Changelog));
421 return $classify->(qw(Packaging));
423 } elsif ($ty eq 'missing') {
424 return $classify->(qw(BreakwaterStart));
426 return $unknown->("parent's debian is not a directory");
428 } elsif ($d == D_UPS) {
429 return $classify->(qw(Upstream));
430 } elsif ($d & DS_DEB and $d & D_UPS and !($d & ~(DS_DEB|D_UPS))) {
431 return $classify->(qw(Mixed));
433 return $unknown->("no changes");
435 confess "internal error $objid ?";
439 return $unknown->("origin commit");
442 my @identical = grep { !$_->{Differs} } @p;
443 if (@p == 2 && @identical == 1 && !$claims_to_be_breakwater
444 # breakwater merges can look like pseudomerges, if they are
445 # "declare" commits (ie, there are no upstream changes)
447 my @overwritten = grep { $_->{Differs} } @p;
448 confess "internal error $objid ?" unless @overwritten==1;
449 return $classify->(qw(Pseudomerge),
450 Overwritten => [ $overwritten[0] ],
451 Contributor => $identical[0]);
453 if (@p == 2 && @identical == 2) {
455 my ($ph,$pm) = get_commit $_[0]{CommitId};
456 $ph =~ m/^committer .* (\d+) [-+]\d+$/m or die "$_->{CommitId} ?";
460 my $order = $get_t->($bytime[0]) <=> $get_t->($bytime[1]);
461 if ($order > 0) { # newer first
462 } elsif ($order < 0) {
463 @bytime = reverse @bytime;
465 # same age, default to order made by -s ours
466 # that is, commit was made by someone who preferred L
468 return $classify->(qw(Pseudomerge),
469 SubType => qw(Ambiguous),
470 Contributor => $bytime[0],
471 Overwritten => [ $bytime[1] ]);
474 my ($p_h, $p_m) = get_commit $p->{CommitId};
475 $p->{IsOrigin} = $p_h !~ m/^parent \w+$/m;
476 ($p->{IsDgitImport},) = $p_m =~ m/^\[dgit import ([0-9a-z]+) .*\]$/m;
478 my @orig_ps = grep { ($_->{IsDgitImport}//'X') eq 'orig' } @p;
480 if (!(grep { !$_->{IsOrigin} } @p) and
481 (@orig_ps >= @p - 1) and
482 $m2 =~ s{^\[(dgit import unpatched .*)\]$}{[was: $1]}m) {
484 return $classify->(qw(DgitImportUnpatched),
485 OrigParents => \@orig_ps);
488 my ($stype, $series) = git_cat_file "$t:debian/patches/series";
489 my $haspatches = $stype ne 'missing' && $series =~ m/^\s*[^#\n\t ]/m;
491 # How to decide about l/r ordering of breakwater merges ? git
492 # --topo-order prefers to expand 2nd parent first. There's
493 # already an easy rune to look for debian/ history anyway (git log
494 # debian/) so debian breakwater branch should be 1st parent; that
495 # way also there's also an easy rune to look for the upstream
496 # patches (--topo-order).
498 # The above tells us which way *we* will generate them. But we
499 # might encounter ad-hoc breakwater merges generated manually,
500 # which might be the other way around. In principle, in some odd
501 # situations, a breakwater merge might have two identical parents.
502 # In that case we guess which way round it is (ie, which parent
503 # has the upstream history). The order of the 2-iteration loop
504 # controls which guess we make.
506 foreach my $prevbrw (qw(0 1)) {
509 !$p[$prevbrw]{IsOrigin} && # breakwater never starts with an origin
510 !($p[!$prevbrw]{Differs} & ~DS_DEB) && # no non-debian changess
511 !($p[$prevbrw]{Differs} & ~D_UPS)) { # no non-upstream changes
512 return $classify->(qw(BreakwaterUpstreamMerge),
513 OrigParents => [ $p[!$prevbrw] ]);
517 # multi-orig upstreams are represented with a breakwater merge
518 # from a single upstream commit which combines the orig tarballs
520 return $unknown->("complex merge");
523 sub breakwater_of ($) {
524 my ($head) = @_; # must be laundered
528 fail "branch needs laundering (run git-debrebase): $why";
531 my $cl = classify $head;
532 my $ty = $cl->{Type};
533 if ($ty eq 'Packaging' or
534 $ty eq 'Changelog') {
535 $breakwater //= $head;
536 } elsif ($ty eq 'BreakwaterUpstreamMerge' or
537 $ty eq 'BreakwaterStart') {
538 $breakwater //= $head;
540 } elsif ($ty eq 'Upstream') {
541 $unclean->("packaging change ($breakwater)".
542 " follows upstream change (eg $head)")
543 if defined $breakwater;
544 } elsif ($ty eq 'Mixed') {
545 $unclean->('found mixed upstream/packaging commit ($head)');
546 } elsif ($ty eq 'Pseudomerge' or
547 $ty eq 'AddPatches') {
548 $unclean->("found interchange conversion commit ($ty, $head)");
549 } elsif ($ty eq 'DgitImportUnpatched') {
550 $unclean->("found dgit dsc import ($head)");
552 fail "found unprocessable commit, cannot cope: $head; $cl->{Why}";
554 $head = $cl->{Parents}[0]{CommitId};
562 $nogenerate,$report) = @_;
563 # => ($tip, $breakwater_tip, $last_upstream_merge_in_breakwater)
564 # (or nothing, if $nogenerate)
566 printdebug "*** WALK $input ".($nogenerate//0)." ".($report//'-')."\n";
568 # go through commits backwards
569 # we generate two lists of commits to apply:
570 # breakwater branch and upstream patches
571 my (@brw_cl, @upp_cl, @processed);
578 my ($prose, $info) = @_;
582 $ms .= "\n\n[git-debrebase$info: $prose]\n";
585 my $rewrite_from_here = sub {
586 my $sp_cl = { SpecialMethod => 'StartRewrite' };
587 push @brw_cl, $sp_cl;
588 push @processed, $sp_cl;
593 my $prprdelim = sub { print $report $prdelim if $report; $prdelim=""; };
596 return unless $report;
597 print $report $prdelim, @_;
601 my $bomb = sub { # usage: return $bomb->();
602 print $report " Unprocessable" if $report;
603 print $report " ($cl->{Why})" if $report && defined $cl->{Why};
606 return (undef,undef);
608 die "commit $cur: Cannot cope with this commit (d.".
609 (join ' ', map { sprintf "%#x", $_->{Differs} }
610 @{ $cl->{Parents} }).
611 (defined $cl->{Why} ? "; $cl->{Why}": '').
618 my $build_start = sub {
619 my ($msg, $parent) = @_;
622 no warnings qw(exiting); last;
625 my $last_upstream_update;
629 my $ty = $cl->{Type};
630 my $st = $cl->{SubType};
631 $prline->("$cl->{CommitId} $cl->{Type}");
632 $found{$ty. ( defined($st) ? "-$st" : '' )}++;
633 push @processed, $cl;
634 my $p0 = @{ $cl->{Parents} }==1 ? $cl->{Parents}[0]{CommitId} : undef;
635 if ($ty eq 'AddPatches') {
637 $rewrite_from_here->();
639 } elsif ($ty eq 'Packaging' or $ty eq 'Changelog') {
643 } elsif ($ty eq 'BreakwaterStart') {
644 $last_upstream_update = $cur;
645 $build_start->('FirstPackaging', $cur);
646 } elsif ($ty eq 'Upstream') {
650 } elsif ($ty eq 'Mixed') {
653 my $cls = { %$cl, $xmsg->("split mixed commit: $wh part") };
656 $queue->(\@brw_cl, "debian");
657 $queue->(\@upp_cl, "upstream");
658 $rewrite_from_here->();
661 } elsif ($ty eq 'Pseudomerge') {
662 my $contrib = $cl->{Contributor}{CommitId};
663 print $report " Contributor=$contrib" if $report;
664 push @pseudomerges, $cl;
665 $rewrite_from_here->();
668 } elsif ($ty eq 'BreakwaterUpstreamMerge') {
669 $last_upstream_update = $cur;
670 $build_start->("PreviousBreakwater", $cur);
671 } elsif ($ty eq 'DgitImportUnpatched') {
672 my $pm = $pseudomerges[-1];
674 # To an extent, this is heuristic. Imports don't have
675 # a useful history of the debian/ branch. We assume
676 # that the first pseudomerge after an import has a
677 # useful history of debian/, and ignore the histories
678 # from later pseudomerges. Often the first pseudomerge
679 # will be the dgit import of the upload to the actual
680 # suite intended by the non-dgit NMUer, and later
681 # pseudomerges may represent in-archive copies.
682 my $ovwrs = $pm->{Overwritten};
683 printf $report " PM=%s \@Overwr:%d",
684 $pm->{CommitId}, (scalar @$ovwrs)
687 printdebug "*** WALK BOMB DgitImportUnpatched\n";
690 my $ovwr = $ovwrs->[0]{CommitId};
691 printf $report " Overwr=%s", $ovwr if $report;
692 # This import has a tree which is just like a
693 # breakwater tree, but it has the wrong history. It
694 # ought to have the previous breakwater (which the
695 # pseudomerge overwrote) as an ancestor. That will
696 # make the history of the debian/ files correct. As
697 # for the upstream version: either it's the same as
698 # was ovewritten (ie, same as the previous
699 # breakwater), in which case that history is precisely
700 # right; or, otherwise, it was a non-gitish upload of a
701 # new upstream version. We can tell these apart by
702 # looking at the tree of the supposed upstream.
705 SpecialMethod => 'DgitImportDebianUpdate',
706 $xmsg->("convert dgit import: debian changes")
709 SpecialMethod => 'DgitImportUpstreamUpdate',
710 $xmsg->("convert dgit import: upstream update",
713 $prline->(" Import");
714 $rewrite_from_here->();
715 $upp_limit //= $#upp_cl; # further, deeper, patches discarded
719 # Everything is from this import. This kind of import
720 # is already in valid breakwater format, with the
721 # patches as commits.
722 printf $report " NoPM" if $report;
723 # last thing we processed will have been the first patch,
724 # if there is one; which is fine, so no need to rewrite
725 # on account of this import
726 $build_start->("ImportOrigin", $cur);
730 printdebug "*** WALK BOMB unrecognised\n";
736 printdebug "*** WALK prep done cur=$cur".
737 " brw $#brw_cl upp $#upp_cl proc $#processed pm $#pseudomerges\n";
739 return if $nogenerate;
741 # Now we build it back up again
747 my $read_tree_debian = sub {
749 read_tree_subdir 'debian', "$treeish:debian";
750 rm_subdir_cached 'debian/patches';
752 my $read_tree_upstream = sub {
754 runcmd @git, qw(read-tree), $treeish;
755 $read_tree_debian->($build);
758 $#upp_cl = $upp_limit if defined $upp_limit;
760 my $committer_authline = calculate_committer_authline();
762 printdebug "WALK REBUILD $build ".(scalar @processed)."\n";
764 confess "internal error" unless $build eq (pop @processed)->{CommitId};
767 mkdir $rd or $!==EEXIST or die $!;
769 runcmd @git, qw(read-tree), $build;
770 foreach my $cl (qw(Debian), (reverse @brw_cl),
771 { SpecialMethod => 'RecordBreakwaterTip' },
772 qw(Upstream), (reverse @upp_cl)) {
774 $current_method = $cl;
777 my $method = $cl->{SpecialMethod} // $current_method;
778 my @parents = ($build);
779 my $cltree = $cl->{CommitId};
780 printdebug "WALK BUILD ".($cltree//'undef').
781 " $method (rewriting=$rewriting)\n";
782 if ($method eq 'Debian') {
783 $read_tree_debian->($cltree);
784 } elsif ($method eq 'Upstream') {
785 $read_tree_upstream->($cltree);
786 } elsif ($method eq 'StartRewrite') {
789 } elsif ($method eq 'RecordBreakwaterTip') {
790 $breakwater = $build;
792 } elsif ($method eq 'DgitImportDebianUpdate') {
793 $read_tree_debian->($cltree);
794 } elsif ($method eq 'DgitImportUpstreamUpdate') {
795 confess unless $rewriting;
796 my $differs = (get_differs $build, $cltree);
797 next unless $differs & D_UPS;
798 $read_tree_upstream->($cltree);
799 push @parents, map { $_->{CommitId} } @{ $cl->{OrigParents} };
804 my $procd = (pop @processed) // 'UNDEF';
807 printdebug "WALK REWRITING NOW cl=$cl procd=$procd\n";
810 my $newtree = cmdoutput @git, qw(write-tree);
812 $ch =~ s{^tree .*}{tree $newtree}m or confess "$ch ?";
813 $ch =~ s{^parent .*\n}{}mg;
814 $ch =~ s{(?=^author)}{
815 join '', map { "parent $_\n" } @parents
816 }me or confess "$ch ?";
818 $ch =~ s{^committer .*$}{$committer_authline}m
821 my $cf = "$rd/m$rewriting";
822 open CD, ">", $cf or die $!;
823 print CD $ch, "\n", $cl->{Msg} or die $!;
825 my @cmd = (@git, qw(hash-object));
826 push @cmd, qw(-w) if $rewriting;
827 push @cmd, qw(-t commit), $cf;
828 my $newcommit = cmdoutput @cmd;
829 confess "$ch ?" unless $rewriting or $newcommit eq $cl->{CommitId};
831 if (grep { $method eq $_ } qw(DgitImportUpstreamUpdate)) {
832 $last_upstream_update = $cur;
837 my $final_check = get_differs $build, $input;
838 die sprintf "internal error %#x %s %s", $final_check, $build, $input
839 if $final_check & ~D_PAT_ADD;
841 my @r = ($build, $breakwater, $last_upstream_update);
842 printdebug "*** WALK RETURN @r\n";
847 git_check_unmodified();
848 return git_rev_parse qw(HEAD);
851 sub update_head ($$$) {
852 my ($old, $new, $mrest) = @_;
853 runcmd @git, qw(update-ref -m), "debrebase: $mrest", 'HEAD', $new, $old;
856 sub update_head_checkout ($$$) {
857 my ($old, $new, $mrest) = @_;
858 update_head $old, $new, $mrest;
859 runcmd @git, qw(reset --hard);
862 sub update_head_postlaunder ($$$) {
863 my ($old, $tip, $reflogmsg) = @_;
864 return if $tip eq $old;
865 print "git-debrebase: laundered (head was $old)\n";
866 update_head $old, $tip, $reflogmsg;
867 # no tree changes except debian/patches
868 runcmd @git, qw(rm --quiet --ignore-unmatch -rf debian/patches);
872 badusage "no arguments to launder allowed" if @ARGV;
873 my $old = get_head();
874 my ($tip,$breakwater,$last_upstream_merge) = walk $old;
875 update_head_postlaunder $old, $tip, 'launder';
876 printf "# breakwater tip\n%s\n", $breakwater;
877 printf "# working tip\n%s\n", $tip;
878 printf "# last upstream merge\n%s\n", $last_upstream_merge;
881 sub defaultcmd_rebase () {
882 my $old = get_head();
883 my ($status, $message) = record_ffq_prev();
884 if ($status eq 'written' || $status eq 'exists') {
886 fproblem $status, "could not record ffq-prev: $message";
887 fproblems_maybe_bail();
889 my ($tip,$breakwater) = walk $old;
890 update_head_postlaunder $old, $tip, 'launder for rebase';
891 runcmd @git, qw(rebase), @ARGV, $breakwater;
895 die if ($ARGV[0]//'') =~ m/^-/;
896 badusage "too many arguments to analyse" if @ARGV>1;
899 $old = git_rev_parse $old;
901 $old = git_rev_parse 'HEAD';
903 my ($dummy,$breakwater) = walk $old, 1,*STDOUT;
904 STDOUT->error and die $!;
907 sub ffq_prev_branchinfo () {
908 # => ('status', "message", [$current, $ffq_prev])
910 # branch message is undef
911 # weird-symref } no $current,
912 # notbranch } no $ffq_prev
913 my $current = git_get_symref();
914 return ('detached', 'detached HEAD') unless defined $current;
915 return ('weird-symref', 'HEAD symref is not to refs/')
916 unless $current =~ m{^refs/};
917 my $ffq_prev = "refs/$ffq_refprefix/$'";
918 printdebug "ffq_prev_branchinfo branch current $current\n";
919 return ('branch', undef, $current, $ffq_prev);
922 sub record_ffq_prev () {
923 # => ('status', "message")
925 # written message is undef
930 # if not ff from some branch we should be ff from, is an fproblem
931 # if "written", will have printed something about that to stdout,
932 # and also some messages about ff checks
933 my ($status, $message, $current, $ffq_prev) = ffq_prev_branchinfo();
934 return ($status, $message) unless $status eq 'branch';
936 my $currentval = get_head();
938 my $exists = git_get_ref $ffq_prev;
939 return ('exists',"$ffq_prev already exists") if $exists;
941 return ('not-branch', 'HEAD symref is not to refs/heads/')
942 unless $current =~ m{^refs/heads/};
945 my @check_specs = split /\;/, (cfg "branch.$branch.ffq-ffrefs",1) // '*';
948 printdebug "ffq check_specs @check_specs\n";
951 my ($lrref, $desc) = @_;
952 printdebug "ffq might check $lrref ($desc)\n";
954 for my $chk (@check_specs) {
956 $invert = $glob =~ s{^[!^]}{};
957 last if fnmatch $glob, $lrref;
960 my $lrval = git_get_ref $lrref;
961 return unless defined $lrval;
963 if (is_fast_fwd $lrval, $currentval) {
964 print "OK, you are ahead of $lrref\n" or die $!;
965 $checked{$lrref} = 1;
966 } elsif (is_fast_fwd $currentval, $lrval) {
967 $checked{$lrref} = -1;
968 fproblem 'behind', "you are behind $lrref, divergence risk";
970 $checked{$lrref} = -1;
971 fproblem 'diverged', "you have diverged from $lrref";
975 my $merge = cfg "branch.$branch.merge",1;
976 if (defined $merge and $merge =~ m{^refs/heads/}) {
978 printdebug "ffq merge $rhs\n";
979 my $check_remote = sub {
980 my ($remote, $desc) = @_;
981 printdebug "ffq check_remote ".($remote//'undef')." $desc\n";
982 return unless defined $remote;
983 $check->("refs/remotes/$remote/$rhs", $desc);
985 $check_remote->((scalar cfg "branch.$branch.remote",1),
986 'remote fetch/merge branch');
987 $check_remote->((scalar cfg "branch.$branch.pushRemote",1) //
988 (scalar cfg "branch.$branch.pushDefault",1),
989 'remote push branch');
991 if ($branch =~ m{^dgit/}) {
992 $check->("refs/remotes/dgit/$branch", 'remote dgit branch');
993 } elsif ($branch =~ m{^master$}) {
994 $check->("refs/remotes/dgit/dgit/sid", 'remote dgit branch for sid');
997 fproblems_maybe_bail();
998 runcmd @git, qw(update-ref -m), "record current head for preservation",
999 $ffq_prev, $currentval, $git_null_obj;
1000 print "Recorded current head for preservation\n" or die $!;
1001 return ('written', undef);
1004 sub cmd_new_upstream_v0 () {
1005 # automatically and unconditionally launders before rebasing
1006 # if rebase --abort is used, laundering has still been done
1010 badusage "need NEW-VERSION UPS-COMMITTISH" unless @ARGV >= 2;
1012 # parse args - low commitment
1013 my $new_version = (new Dpkg::Version scalar(shift @ARGV), check => 1);
1014 my $new_upstream_version = $new_version->version();
1016 my $new_upstream = git_rev_parse shift @ARGV;
1019 my ($n, @x) = @_; # may be ''
1020 my $pc = $pieces{$n} //= {
1022 Desc => ($n ? "upstream piece \`$n'" : "upstream (main piece"),
1024 while (my $k = shift @x) { $pc->{$k} = shift @x; }
1029 my $newpiece = sub {
1030 my ($n, @x) = @_; # may be ''
1031 my $pc = $piece->($n, @x, NewIx => (scalar @newpieces));
1032 push @newpieces, $pc;
1037 New => $new_upstream,
1039 while (@ARGV && $ARGV[0] !~ m{^-}) {
1040 my $n = shift @ARGV;
1042 badusage "for each EXTRA-UPS-NAME need EXTRA-UPS-COMMITISH"
1043 unless @ARGV && $ARGV[0] !~ m{^-};
1045 my $c = git_rev_parse shift @ARGV;
1046 die unless $n =~ m/^$extra_orig_namepart_re$/;
1047 $newpiece->($n, New => $c);
1050 # now we need to investigate the branch this generates the
1051 # laundered version but we don't switch to it yet
1052 my $old_head = get_head();
1053 my ($old_laundered_tip,$old_bw,$old_upstream_update) = walk $old_head;
1055 my $old_bw_cl = classify $old_bw;
1056 my $old_upstream_update_cl = classify $old_upstream_update;
1057 confess unless $old_upstream_update_cl->{OrigParents};
1058 my $old_upstream = parsecommit
1059 $old_upstream_update_cl->{OrigParents}[0]{CommitId};
1061 $piece->('', Old => $old_upstream->{CommitId});
1063 if ($old_upstream->{Msg} =~ m{^\[git-debrebase }m) {
1064 if ($old_upstream->{Msg} =~
1065 m{^\[git-debrebase upstream-combine \.((?: $extra_orig_namepart_re)+)\:.*\]$}m
1067 my @oldpieces = ('', split / /, $1);
1068 my $parentix = -1 + scalar @{ $old_upstream->{Parents} };
1069 foreach my $i (0..$#oldpieces) {
1070 my $n = $oldpieces[$i];
1071 $piece->($n, Old => $old_upstream->{CommitId}.'^'.$parentix);
1074 fproblem 'upstream-confusing',
1075 "previous upstream $old_upstream->{CommitId} is from".
1076 " git-debrebase but not an \`upstream-combine' commit";
1080 foreach my $pc (values %pieces) {
1082 fproblem 'upstream-new-piece',
1083 "introducing upstream piece \`$pc->{Name}'";
1084 } elsif (!$pc->{New}) {
1085 fproblem 'upstream-rm-piece',
1086 "dropping upstream piece \`$pc->{Name}'";
1087 } elsif (!is_fast_fwd $pc->{Old}, $pc->{New}) {
1088 fproblem 'upstream-not-ff',
1089 "not fast forward: $pc->{Name} $pc->{Old}..$pc->{New}";
1093 printdebug "%pieces = ", (dd \%pieces), "\n";
1094 printdebug "\@newpieces = ", (dd \@newpieces), "\n";
1096 fproblems_maybe_bail();
1102 my @upstream_merge_parents;
1104 if (!any_fproblems()) {
1105 push @upstream_merge_parents, $old_upstream->{CommitId};
1108 foreach my $pc (@newpieces) { # always has '' first
1110 read_tree_subdir $pc->{Name}, $pc->{New};
1112 runcmd @git, qw(read-tree), $pc->{New};
1114 push @upstream_merge_parents, $pc->{New};
1117 # index now contains the new upstream
1119 if (@newpieces > 1) {
1120 # need to make the upstream subtree merge commit
1121 $new_upstream = make_commit \@upstream_merge_parents,
1122 [ "Combine upstreams for $new_upstream_version",
1123 ("[git-debrebase upstream-combine . ".
1124 (join " ", map { $_->{Name} } @newpieces[1..$#newpieces]).
1129 # $new_upstream is either the single upstream commit, or the
1130 # combined commit we just made. Either way it will be the
1131 # "upstream" parent of the breakwater special merge.
1133 read_tree_subdir 'debian', "$old_bw:debian";
1135 # index now contains the breakwater merge contents
1136 $new_bw = make_commit [ $old_bw, $new_upstream ],
1137 [ "Update to upstream $new_upstream_version",
1138 "[git-debrebase breakwater: new upstream $new_upstream_version, merge]",
1141 # Now we have to add a changelog stanza so the Debian version
1143 die if unlink "debian";
1144 die $! unless $!==ENOENT or $!==ENOTEMPTY;
1145 unlink "debian/changelog" or $!==ENOENT or die $!;
1146 mkdir "debian" or die $!;
1147 open CN, ">", "debian/changelog" or die $!;
1148 my $oldclog = git_cat_file ":debian/changelog";
1149 $oldclog =~ m/^($package_re) \(\S+\) / or
1150 fail "cannot parse old changelog to get package name";
1152 print CN <<END, $oldclog or die $!;
1153 $p ($new_version) UNRELEASED; urgency=medium
1155 * Update to new upstream version $new_upstream_version.
1161 runcmd @git, qw(update-index --add --replace), 'debian/changelog';
1163 # Now we have the final new breakwater branch in the index
1164 $new_bw = make_commit [ $new_bw ],
1165 [ "Update changelog for new upstream $new_upstream_version",
1166 "[git-debrebase: new upstream $new_upstream_version, changelog]",
1170 # we have constructed the new breakwater. we now need to commit to
1171 # the laundering output, because git-rebase can't easily be made
1172 # to make a replay list which is based on some other branch
1174 update_head_postlaunder $old_head, $old_laundered_tip,
1175 'launder for new upstream';
1177 my @cmd = (@git, qw(rebase --onto), $new_bw, $old_bw, @ARGV);
1179 # now it's for the user to sort out
1182 sub cmd_record_ffq_prev () {
1183 badusage "no arguments allowed" if @ARGV;
1184 my ($status, $msg) = record_ffq_prev();
1185 if ($status eq 'exists' && $opt_noop_ok) {
1186 print "Previous head already recorded\n" or die $!;
1187 } elsif ($status eq 'written') {
1189 fail "Could not preserve: $msg";
1193 sub cmd_breakwater () {
1194 badusage "no arguments allowed" if @ARGV;
1195 my $bw = breakwater_of git_rev_parse 'HEAD';
1196 print "$bw\n" or die $!;
1201 GetOptions('prose=s', \$prose) or die badusage("bad options to stitch");
1202 badusage "no arguments allowed" if @ARGV;
1203 my ($status, $message, $current, $ffq_prev) = ffq_prev_branchinfo();
1204 if ($status ne 'branch') {
1205 fproblem $status, "could not check ffq-prev: $message";
1206 fproblems_maybe_bail();
1208 my $prev = $ffq_prev && git_get_ref $ffq_prev;
1210 fail "No ffq-prev to stitch." unless $opt_noop_ok;
1213 my $old_head = get_head();
1214 my $new_head = make_commit [ $old_head, $ffq_prev ], [
1215 'Declare fast forward / record previous work',
1216 "[git-debrebase pseudomerge: stitch$prose]",
1218 my @upd_cmd = (@git, qw(update-ref --stdin));
1219 debugcmd '>|', @upd_cmd;
1220 open U, "|-", @upd_cmd or die $!;
1222 update HEAD $new_head $old_head
1223 delete $ffq_prev $prev
1225 printdebug ">= ", $_, "\n" foreach split /\n/, $u;
1228 close U or failedcmd @upd_cmd;
1231 sub cmd_convert_from_gbp () {
1232 badusage "needs 1 optional argument, the upstream git rev"
1234 my ($upstream_spec) = @ARGV;
1235 $upstream_spec //= 'refs/heads/upstream';
1236 my $upstream = git_rev_parse $upstream_spec;
1237 my $old_head = get_head();
1239 my $upsdiff = get_differs $upstream, $old_head;
1240 if ($upsdiff & D_UPS) {
1241 runcmd @git, qw(--no-pager diff),
1242 $upstream, $old_head,
1243 qw( -- :!/debian :/);
1244 fail "upstream ($upstream_spec) and HEAD are not identical in upstream files";
1247 if (!is_fast_fwd $upstream, $old_head) {
1248 fproblem 'upstream-not-ancestor',
1249 "upstream ($upstream) is not an ancestor of HEAD";
1251 my $wrong = cmdoutput
1252 (@git, qw(rev-list --ancestry-path), "$upstream..HEAD",
1253 qw(-- :/ :!/debian));
1254 if (length $wrong) {
1255 fproblem 'unexpected-upstream-changes',
1256 "history between upstream ($upstream) and HEAD contains direct changes to upstream files - are you sure this is a gbp (patches-unapplied) branch?";
1257 print STDERR "list expected changes with: git log --stat --ancestry-path $upstream_spec..HEAD -- :/ ':!/debian'\n";
1261 if ((git_cat_file "$upstream:debian")[0] ne 'missing') {
1262 fproblem 'upstream-has-debian',
1263 "upstream ($upstream) contains debian/ directory";
1266 fproblems_maybe_bail();
1272 runcmd @git, qw(checkout -q -b gdr-internal), $old_head;
1273 # make a branch out of the patch queue - we'll want this in a mo
1274 runcmd qw(gbp pq import);
1275 # strip the patches out
1276 runcmd @git, qw(checkout -q gdr-internal~0);
1277 rm_subdir_cached 'debian/patches';
1278 $work = make_commit ['HEAD'], [
1279 'git-debrebase convert-from-gbp: drop patches from tree',
1280 'Delete debian/patches, as part of converting to git-debrebase format.',
1281 '[git-debrebase convert-from-gbp: drop patches from tree]'
1283 # make the breakwater pseudomerge
1284 # the tree is already exactly right
1285 $work = make_commit [$work, $upstream], [
1286 'git-debrebase import: declare upstream',
1287 'First breakwater merge.',
1288 '[git-debrebase breakwater: declare upstream]'
1291 # rebase the patch queue onto the new breakwater
1292 runcmd @git, qw(reset --quiet --hard patch-queue/gdr-internal);
1293 runcmd @git, qw(rebase --quiet --onto), $work, qw(gdr-internal);
1294 $work = git_rev_parse 'HEAD';
1297 update_head_checkout $old_head, $work, 'convert-from-gbp';
1300 sub cmd_convert_to_gbp () {
1301 badusage "no arguments allowed" if @ARGV;
1302 my $head = get_head();
1303 my $ffq = (ffq_prev_branchinfo())[3];
1304 my $bw = breakwater_of $head;
1308 runcmd @git, qw(checkout -q -b bw), $bw;
1309 runcmd @git, qw(checkout -q -b patch-queue/bw), $head;
1310 runcmd qw(gbp pq export);
1311 runcmd @git, qw(add debian/patches);
1312 $out = make_commit ['HEAD'], [
1313 'Commit patch queue (converted from git-debrebase format)',
1314 '[git-debrebase convert-to-gbp: commit patches]',
1318 runcmd @git, qw(update-ref -m),
1319 "debrebase: converting corresponding main branch to gbp format",
1320 $ffq, $git_null_obj;
1322 update_head_checkout $head, $out, "convert to gbp (v0)";
1323 print <<END or die $!;
1324 git-debrebase: converted to git-buildpackage branch format
1325 git-debrebase: WARNING: do not now run "git-debrebase" any more
1326 git-debrebase: WARNING: doing so would drop all upstream patches!
1330 sub cmd_downstream_rebase_launder_v0 () {
1331 badusage "needs 1 argument, the baseline" unless @ARGV==1;
1333 $base = git_rev_parse $base;
1334 my $old_head = get_head();
1335 my $current = $old_head;
1338 if ($current eq $base) {
1339 $topmost_keep //= $current;
1340 print " $current BASE stop\n";
1343 my $cl = classify $current;
1344 print " $current $cl->{Type}";
1346 my $p0 = $cl->{Parents}[0]{CommitId};
1348 if ($cl->{Type} eq 'Pseudomerge') {
1349 print " ^".($cl->{Contributor}{Ix}+1);
1350 $next = $cl->{Contributor}{CommitId};
1351 } elsif ($cl->{Type} eq 'AddPatches' or
1352 $cl->{Type} eq 'Changelog') {
1362 $topmost_keep //= $current;
1364 die "to-be stripped changes not on top of the branch\n"
1369 if ($topmost_keep eq $old_head) {
1370 print "unchanged\n";
1372 print "updating to $topmost_keep\n";
1373 update_head_checkout
1374 $old_head, $topmost_keep,
1375 'downstream-rebase-launder-v0';
1379 GetOptions("D+" => \$debuglevel,
1380 'noop-ok', => \$opt_noop_ok,
1381 'f=s' => \@fproblem_force_opts,
1382 'force!') or die badusage "bad options\n";
1383 initdebug('git-debrebase ');
1384 enabledebug if $debuglevel;
1386 my $toplevel = cmdoutput @git, qw(rev-parse --show-toplevel);
1387 chdir $toplevel or die "chdir $toplevel: $!";
1389 $rd = fresh_playground "$playprefix/misc";
1391 if (!@ARGV || $ARGV[0] =~ m{^-}) {
1392 defaultcmd_rebase();
1394 my $cmd = shift @ARGV;
1397 $cmdfn = ${*::}{"cmd_$cmdfn"};
1399 $cmdfn or badusage "unknown git-debrebase sub-operation $cmd";